- dsp.biphase_raw_decode: faithful port of lfdemod.c BiphaseRawDecode (pairwise
differential-Manchester decode with phase-fault offset nudge + error markers).
- protocols.decode_fdxb: ASK + biphase, find the 00000000001 preamble, de-interleave
the 8-bit data groups (every 9th bit a control 1), reassemble the 10-bit country +
38-bit national code. Accepted only when the CRC-16 over the eight data bytes matches
the stored one, so it can't false-positive. Both biphase polarities tried.
- protocols.crc16 / crc16_fdxb: parametric bitwise CRC-16 (Rocksoft model) matching the
firmware crc16_fast; FDX-B is poly 0x1021, init 0, refin=false, refout=true.
Added to the identify decoder chain (FDX-B is common in implants).
Tests: FDX-B round-trip (country/national/animal), CRC gate rejects noise/EM4100, and
a CRC known-answer test pinning the impl to CRC-16/XMODEM (0x31C3) and KERMIT (0x2189).
Full suite green.
Indala (PSK) + AWID queued.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>